PORT-AU-PRINCE, Haiti (AP) — Tropical Storm Emily spun slowly to the south of the Dominican Republic and Haiti Wednesday night, its strong winds already shaking palm trees and threatening tens of thousands of people in flimsy shelters and tents.

The storm was forecast to make landfall on Haiti's southern peninsula early Thursday and dump torrential rains across an impoverished country in which more than 600,000 people still live without shelter after last year's earthquake.

"If any storm comes, we meet our demise," said Renel Joseph, a 57-year-old resident of Cite Soleil, a seaside shantytown of Haiti's capital.

David Preux, head of mission for the International Organization for Migration in the southern city of Jacmel, said that wind, rain and lightning had begun Wednesday night. "It'll get worse overnight."

"The problem is when people wait until the last minute to evacuate," Preux said.

The storm had stalled off the coast of the Dominican Republic but appeared set to skirt that country's southern tip. It had maximum sustained winds of 50 mph (85 kph).

Dominican authorities dropped a tropical storm warning Wednesday night from Cabo Francis Viejo southeastward to Cabo Engano. One remained in effect along the southwestern coast.

But the intense rain still posed a threat to the two nations that share the island of Hispaniola, said Diana Goeller, a meteorologist with the U.S. National Hurricane Center. The countries are divided by a range of high mountains.

"This storm has a lot of heavy rainfall with it," Goeller told The Associated Press. "So in those mountainous areas, there could be very dangerous, life-threatening mudslides or flash floods."

John Cangialosi, a hurricane specialist with the hurricane center, said that though Emily's eye would pass over southwestern Haiti, the entire country was at risk for major rain, with up to 20 inches (50 centimeters) possible in isolated high-elevation areas. That is enough to cause serious problems in a country prone to catastrophic flooding.

"Rainfall-wise, the whole country is going to get a significant amount of rain," Cangialosi told The Associated Press.

A U.N. aid group distributed cholera prevention kits to help fight the waterborne disease, and the government set up a network of shelters.

Francois Prophete, who was shoring up the corrugated-metal roof of his one-room cinder block home in the hills southeast of Port-au-Prince, said most people had few options in a nation where the vast majority are desperately poor. "We can't afford to do much," he said.

Michel Davison of the U.S. National Oceanic and Atmospheric Administration said the storm had earlier dropped up to 10 inches (250 millimeters) of rain in parts of Puerto Rico, though its center never got within 100 miles (160 kilometers) of the island.

Civil defense officials and the military in the Dominican Republic moved dozens of families out of high-risk zones ahead of the storm. Fourteen commercial and cargo flights into Santo Domingo were canceled and two others were delayed.

Batista Geovanny nailed down the tin roof of his house near the Ozama river in Santo Domingo.

"You never know what might happen," said Batista, fearful that the riverbank outside his front door might burst.

In Haiti, local authorities urged people to conserve food and safeguard their belongings and prepared a fleet of buses to evacuate people from flooded areas.

An untold number of people took that advice and volunteered to leave their flood-prone houses to stay with relatives and friends, said Emmanuelle Schneider, a spokeswoman for the United Nations' Office for the Coordination of Humanitarian Affairs. There had been no government-organized evacuations by Wednesday night, she added.

"There will be an official evacuation when there's flooding," said Schneider.

The U.N. force in the country put 11,500 troops on standby to provide aid. The International Red Cross alerted emergency teams that have access to relief supplies already in place for up to 125,000 people throughout the country.

There was reason for concern. A slow-moving storm in June triggered mudslides and floods in Haiti and killed at least 28 people, and widespread poverty makes it difficult for people to take even the most basic precautions.

Joceline Alcide stashed her two kids' birth certificates and school papers in little plastic bags that aid groups handed out. It was her only means to protect herself.

"There really isn't much more we can do. We just got these bags," the 39-year-old Alcide said, standing outside her teepee-like tarp shelter.

That was the same storm that toppled Alcide's previous tent-like shelter, which once stood on the side of a ravine a couple of miles away. Her neighbors saw cinderblock houses slide down the hills in unforgiving mudslides.

Despite the government call to evacuate neighborhoods if there is flooding, Vania Zamor said she had no plans to leave. She feared thieves might break into her sheet metal shack and steal the beans and rice she sells as a merchant.

Besides, "it's going to be very hard for us to leave because people rely on us," said Zamor, a 39-year-old camp leader in a ravine shanty in the Petionville section south of Port-au-Prince.

"If God doesn't protect the people living on the hills, there's going to be a lot of damage."

The National Hurricane Center said the storm was heading west at 14 mph (22 kph) Wednesday night, and it was expected to turn toward the northwest. The storm was about 50 miles (75 kilometers) southeast of Isla Beata in the Dominican Republic and about 135 miles (215 kilometers) southeast of Port-au-Prince.

The wind speed could slow down because of the mountainous terrain in Haiti and eastern Cuba but could strengthen as the storm approaches the Bahamas.